Short-circuit boolean operators

[dgriffie79]

boolean evaluations don't short-circuit, which is surprising. Can this be added?

[brendanfh]

This is something I have been meaning to add for a while but I kept pushing it off because I thought it was going to be harder to implement. With changes I made to some of the data structures used in the code generation step I made last year, this was actually really easy to implement, so the changes are in this branch and will be merged in by the next release, and in nightly sooner than that.

[dgriffie79]

wow thanks!